1. Field of the Invention
The present invention relates to centrifuges and more particularly to centrifuges having a structure for preventing rotation of the stator tube of a rotating vessel.
2. Description of the Related Art
U.S. Pat. No. 4,718,888 to Darnell, and U.S. Pat. Nos. 4,684,361 and 4,692,136 to Feldman et al., which are incorporated herein by reference, each disclose a centrifuge bowl having an attached dip tube assembly, for use in a centrifuge. The bowl is designed to hold liquids, and has a single opening at its upper end through which passes a stationary dip tube assembly (hereafter called the stator assembly). The stator has an inlet and outlet adjacent to the upper end for permitting liquid to be pumped into and pumped from the centrifuge during a centrifuge operation. A similar bowl/stator arrangement is shown in FIG. 1 of the present application and is typically used in connection with a centrifuge which rotates the bowl containing a liquid. When the bowl is rotated at sufficient speeds, fractions of the liquid may be separated. For example, when the liquid is human blood, a centrifuge operation may separate red blood cells from other components of the blood.
During a centrifuge operation using the above-described bowl and stator arrangement, the stator must be maintained in a position so that its inlet and outlet ports remain stationary. Rotational or lateral movement of the stator tube could cause tubes connected to the stator's ports to stretch and break thereby interrupting flow. Similarly, vertical movement of the stator could cause wear and/or destruction of the stator assembly.
Prior to the present invention, a typical centrifuge employed two swing arms to hold the stator in position. For example, U.S. Pat. No. 3,581,981 discloses a centrifuge chuck including two pivoting clamping arms each having an arcuate surface for holding the tube assembly therebetween. However, in the prior art, in order to properly engage the stator of the bowl/stator arrangement of the type shown in FIG. 1 of the present application, two pivoting arms must be moved, the face seal must be manually compressed, and a clamping device must be engaged and tightened. This is a two-handed operation that is difficult for a busy technician who may only have one hand to spare.